The SFD injector invention is designed to improve and overcome the weaknesses and low efficiencies of the old technologies derived from two types of injectors:                g.1 Vacuum-loading Injector technology:                    Referred to as Vacuum-loading Injector, such technology was developed in the 1970's, to replace the carburetor device which had been used since the development of the ICE Engine.                        g.2 The Vacuum-Loading Injector is located on the mixture inlet manifold and is activated when the piston is forced down from the Top Dead Point (TDP) (after the exhaust cycle) to inlet fresh fuel mixture into the cylinder.        g.3 This type of injector does not require a lot of energy to operate, due to the low pressure in the inlet manifold. The time available for loading the fuel mixture in this type of system is ½ of the work cycle, corresponding to a time response of 0.02 of a second, assuming 3000 RPM and ½ of the working cycle.        g.4 The vacuum loading injector was the first injection technology to be introduced, most likely because of the simplicity of the assembly. Since in this process the fuel droplet mixture is introduced into the piston in the pre-compression stage, the process is limited to operating below detonation pressure (pre SFI) and thus is limited to and sensitive to the pre-designed octane, and resulting in low efficiency.        